Description: This external battery pack works with the built-in battery pack to provide power, allowing you to use an external battery pack to extend your riding distance. Our batteries are made from high quality cells to ensure a long service life. Features: Suitable Model: Voyager,Voyager2.0 Capacity: 48V 17.5AH, 840WH Lithium-ion battery, UL tested Battery weighs 6.8 pounds Installation: Backup battery installation guide *Does not come with a charger